The cephalosporin antibiotic ceftiofur, which can be named 7-[2-(2-amino-1,3-thiazol-4-yl)-2-methoxyimino)acetamido]-3-[(fur-2-ylcarb onyl)thiomethyl]-3-cephem-4-carboxylic acid, also named 7-[2-(2-amino-1,3-thiazol-4-yl)-2-methoxyimino)acetamido]-3-[2-(furanylcar bonylthiomethyl)-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-1-carboxyli acid, and its alkali metal, alkaline earth metal and amine salts of the carboxylic acid group, and easily hydrolyzable esters thereof are described and claimed in Labeeuw et al. U.S. Patent 4,464,367.
Those free acid and alkali metal and amine salt and ester forms of this cephalosporin antibiotic, ceftiofur, are somewhat unstable chemically and are obtained as amorphous compounds which are difficult to purify, and are less desirable to work with in manufacturing pharmaceutical formulations containing them. Those patented salts create salt-solid isolation and salt-solid handling problems in a manufacturing plant which those in the pharmaceutical art would prefer to avoid.
A hydrohalide salt of ceftiofur, particularly the hydrochloride salt thereof, was described and claimed in U.S. patent application Serial No. 664,651 filed 25 October 1984. A corresponding South African Patent No. 85/7613 has been published disclosing such ceftiofur hydrohalide salts.
Those in the art of ceftiofur therapy continue to search for improved forms of ceftiofur including forms of ceftiofur which will not only be acceptable to the health and safety authorities for the contemplated antibiotic therapies but which will permit and provide higher bulk density forms of ceftiofur, easier dispersibility of the selected pharmaceutical form of ceftiofur in aqueous and organic diluents and still not be detrimental to the structure of the parent ceftiofur antibiotic itself.